Chemical fractionation and isotopic analysis of lead in sediments from the Taipu River, integrated demonstration zone in the Yangtze River Delta, China

The Taipu River is a crucial water source for residents in the metropolitan area of Shanghai. However, elevated lead (Pb) persists in its sediments, with the distribution, chemical fractionation, and sources of Pb still unclear. The objective of this study was to investigate the chemical fractionation and isotopic compositions of Pb in sediments from the Taipu River in the Integrated Demonstration Zone of the Yangtze River Delta, China. Sediment samples were collected and analyzed for total Pb concentrations, chemical fractionation, and isotopic compositions. The results revealed seasonal variations in Pb concentration within the sediments, with an average of 32.7 mg/kg during the wet season and 38.2 mg/kg during the dry season. The highest concentration was observed in Jiangsu Province (T6), an area known for its textile and electronic power industries. Chemical fractionation analysis indicated that the majority of Pb in the sediments was in the non-residual fraction, accounting for an average of 87.6 % in summer and 92.0 % in winter. This suggests that Pb in Taipu River sediments is readily released into the aquatic environment, posing a significant threat to human health and the environment. Isotopic analysis further revealed that Pb in the sediments primarily originated from anthropogenic sources, including industrial activities, PM10, PM2.5, and urban aerosols, with only a minor contribution from natural sources. These findings provide valuable insights into the sources and behavior of Pb in the Taipu River and can inform the development of effective strategies for controlling Pb contamination. [Display omitted] •Pb surpasses the background levels and was relatively higher during the dry season.•Pb is dominated by non-residual fraction and can be easily released to environment.•The primary sources of Pb pollution are anthropogenic activities.•PM10, PM2.5, and urban aerosols are also potential sources of Pb pollution.